TW201801445A - Wireless power transfer in an electronic device having a tuned metallic body - Google Patents

Abstract

An electronic apparatus may include an electrically conductive body configured to magnetically couple to a first magnetic field. A first tuning element may be connected to the electrically conductive body. An electrically conductive coil may be wound about an opening defined by the electrically conductive body, and configured to magnetically couple to a second magnetic field.

Description

Wireless power transmission in electronic devices with tuned metal bodies

The present invention relates to wireless power transmission, and more specifically, to wireless power transmission in an electronic device having a tuned metal body.

Wireless power transmission is an increasingly common capability in portable electronic devices such as mobile phones, tablets, etc., because these devices typically require long battery life and small battery weight. The ability to power electronic devices without using wires provides a convenient solution for users of portable electronic devices. A wireless power charging system, for example, may allow a user to charge and / or power an electronic device without a physical electrical connection, thereby reducing the number of components required to operate the electronic device and simplifying the use of the electronic device. Wireless power transmission has allowed manufacturers to develop creative solutions to the problems that arise due to limited power sources in consumer electronics devices. Wireless power transmission can reduce overall costs (for both users and manufacturers) because conventional charging hardware, such as power adapters and charging chords, can be removed. Components (e.g. magnetic coils, charging pads, etc.) have different size and shape flexibility. Industrial design compensates for wireless power transmitters and / or wireless power receivers and supports mobile handheld devices to laptops A wide range of devices.

According to aspects of the invention, an electronic device for wireless power transmission may include a conductive body configured to be magnetically coupled to a first magnetic field. A first tuning element can be electrically connected to the conductive body. A conductive coil may be wound around an opening defined by the conductive body; the conductive coil may be configured to be magnetically coupled to a second magnetic field. In some embodiments, the electronic device may further include a second tuning element electrically connected to the conductive coil. Each of the first tuning element and the second tuning element may include one or more capacitors. Either or both of the first tuning element and the second tuning element may further include one or more inductors. In some embodiments, the first magnetic field may be an externally generated magnetic field generated by a wireless power transmitter and the conductive body generates the second magnetic field in response to being coupled to the externally generated magnetic field. The electronic device may further include a rectifier connected to the conductive coil. The rectifier may be configured to rectify a current induced in the conductive coil to provide power to an electronic device including the device. In some embodiments, the second magnetic field may be an externally generated magnetic field and the conductive coil may generate the first magnetic field in response to being coupled to the externally generated magnetic field. The electronic device may further include a rectifier connected to the electrical conductor. The rectifier may be configured to rectify a current induced in the electrical conductor to provide power to an electronic device including the device. In some embodiments, the electronic device may further include a printed circuit board on which the first tuning element is disposed. A connector can electrically connect the first tuning element to the electrical conductor. In some embodiments, the electronic device may further include a printed circuit board. The conductive coil may be disposed between the conductive body and the printed circuit board. The electronic device may further include a ferrite material disposed between the conductive coil and the printed circuit board. In some embodiments, the first tuning element and the electrical conductor may form a circuit having a resonant frequency defined by the first tuning element. The electronic device may further include a second tuning element electrically connected to the conductive coil to define a circuit, the circuit having the resonance substantially equal to the circuit including the first tuning element and the conductor A resonant frequency of frequency. In some embodiments, the second tuning element may be electrically connected to the conductive coil to define a circuit having a resonance frequency different from the resonance frequency of the circuit including the first tuning element and the conductor. In some embodiments, the electronic device may further include a metal casing configured to receive the electronic device. The metal case may include the electrical conductor. In some embodiments, the electronic device may further include a non-metallic housing configured to receive electronic devices containing the device. The conductor and the conductive coil can be housed in the casing. In some embodiments, the device is a wearable electronic device. According to an aspect of the present invention, a method for transmitting wireless power to an electronic device may include magnetically coupling an externally generated magnetic field to a conductive structure (the conductive structure includes a housing for the electronic device) to An induced magnetic field generated from the conductive structure. The induced magnetic field can be magnetically coupled to a power receiving element to sense a current in the power receiving element. The power receiving element may be electrically isolated from the conductive structure. Power can be generated from the current induced in the power receiving element. In some embodiments, a resonance frequency of a circuit including the conductive structure is substantially equal to a frequency of the externally generated magnetic field. In some embodiments, a resonance frequency of a circuit including the power receiving element is substantially equal to a frequency of the externally generated magnetic field. In some embodiments, magnetically coupling the externally generated magnetic field to the conductive structure may include sensing a current in a first circuit, the first circuit including the conductor electrically connected to a first tuning element. Magnetically coupling the induced magnetic field to the power receiving element may include inducing a current in a second circuit, the second circuit including the conductive coil electrically connected to a second tuning element. A resonance frequency of either or both of the first circuit and the second circuit is substantially equal to a frequency of the externally generated magnetic field. In some embodiments, generating power may include rectifying the current induced in the power receiving element. According to aspects of the invention, an electronic device may include a housing configured to enclose an electronic component containing the device. The housing may include a metal portion. A first tuning element is connectable to the metal portion of the housing. The metal portion of the case may have a shape such that an electric current is induced in the case in response to an externally generated magnetic field through magnetic coupling. An induced magnetic field can be emitted from the metal portion in response to the current. The device may include a conductive coil. A current may be induced in the conductive coil in response to being magnetically coupled to the inductive magnetic field to generate a current in the conductive coil. A rectifier can be configured to rectify the current induced in the conductive structure to provide power to a load. In some embodiments, the metal portion of the housing may define an opening therethrough and a slot from the opening to a periphery of the metal portion. In some embodiments, the rectifier may be electrically connected to the conductive coil. In some embodiments, the first tuning element and the metal portion of the housing may define a resonance frequency substantially equal to a resonance frequency defined by the second tuning element and the conductive coil. In some embodiments, the first tuning element and the metal portion of the housing may define a resonance frequency different from a resonance frequency defined by the second tuning element and the conductive coil. According to an aspect of the present invention, a device for wirelessly receiving power in an electronic device may include a component for receiving an electronic device of the electronic device. The member for accommodating may have a metal part including a member for magnetically coupling to an externally generated magnetic field to generate an induced magnetic field, the induced magnetic field being used for the member for magnetically coupling to the externally generated magnetic field. Divergence. The member for magnetic coupling to the externally generated magnetic field is electrically connected to the member for tuning the member for magnetic coupling to the externally generated magnetic field to resonate at a resonance frequency. The device further includes means for magnetically coupling to the inductive magnetic field to induce a current. The member for magnetic coupling to the induced magnetic field is electrically isolated from the member for magnetic coupling to the externally generated magnetic field. The device further includes means for generating power from the current induced in the second member magnetically coupled to the inductive magnetic field. In some embodiments, any one or both of the member for magnetic coupling to the externally generated magnetic field and the member for magnetic coupling to the induced magnetic field has one substantially equal to the externally generated magnetic field. A resonant frequency of frequency. In some embodiments, the component for magnetically coupling to the induced magnetic field includes a conductive coil. The following detailed description and accompanying drawings provide a better understanding of the nature and advantages of the present invention.

In the following description, for the purpose of explanation, numerous examples and specific details are set forth in order to provide a thorough understanding of the present invention. The invention as expressed in the scope of the patent application may include some or all of the features in these examples (alone or in combination with other features described below) and may further include modifications of the features and concepts described herein and Equivalent. Wireless power transmission may refer to the transmission of any form of energy associated with an electric, magnetic, electromagnetic or other field from a transmitter to a receiver (e.g., power can be transmitted via free space) without using physical electrical conductors. Power output to a wireless field (eg, a magnetic or electromagnetic field) can be received, captured, or coupled by a "power receiving element" to enable power transmission. FIG. 1 is a functional block diagram of a wireless power transmission system 100 according to an illustrative embodiment. The input power 102 may be provided from a power source (not shown in this figure) to the transmitter 104 to generate a wireless (eg, magnetic or electromagnetic) field 105 for performing energy transmission. The receiver 108 may be coupled to the wireless field 105 and generate output power 110 for storage or consumption by a device (not shown in this figure) coupled to the output power 110. The transmitter 104 and the receiver 108 can be separated by a distance 112. The transmitter 104 may include a power transmission element 114 for transmitting / coupling energy to the receiver 108. The receiver 108 may include a power receiving element 118 for receiving or capturing / coupling energy transmitted from the transmitter 104. In one illustrative embodiment, the transmitter 104 and the receiver 108 may be configured according to a mutual resonance relationship. When the resonance frequency of the receiver 108 and the transmitter 104 are substantially the same or very close, the transmission loss between the transmitter 104 and the receiver 108 is reduced. Therefore, wireless power transmission can be provided over a large distance. Therefore, resonant inductive coupling technology can allow improved efficiency and power transmission over a variety of distances and with multiple inductive power transmission and reception element configurations. In some embodiments, the wireless field 105 may correspond to the “near field” of the transmitter 104. The near field may correspond to a region in which there is a strong reactance field generated by the current and charge in the power transmission element 114, which reactance field minimizes the power radiation away from the power transmission element 114. The near field may correspond to a region within approximately one wavelength (or a portion thereof) of the power transmission element 114. In some embodiments, efficient energy transmission may be performed by coupling most of the energy in the wireless field 105 to the power receiving element 118 instead of propagating most of the energy to the far field by electromagnetic waves. In some implementations, the transmitter 104 may output a time-varying magnetic field (or electromagnetic field) 105 having a frequency corresponding to the resonant frequency of the power transmission element 114. When the receiver 108 is within the wireless field 105, a time-varying magnetic field (or electromagnetic field) can induce a current in the power receiving element 118. As described above, if the power receiving element 118 is configured as a resonant circuit to resonate at the frequency of the power transmitting element 114, energy can be efficiently transmitted. An alternating current (AC) signal induced in the power receiving element 118 may be rectified to generate a direct current (DC) signal that may be provided to charge or power the load. FIG. 2 is a functional block diagram of a wireless power transmission system 200 according to another illustrative embodiment. The system 200 may include a transmitter 204 and a receiver 208. The transmitter 204 (also referred to herein as a power transmission unit, PTU) may include a transmission circuit 206, which may include an oscillator 222, a driving circuit 224, and a front-end circuit 226. The oscillator 222 may be configured to generate an oscillator signal at a desired frequency, and the desired frequency may be adjusted in response to the frequency control signal 223. The oscillator 222 may provide an oscillator signal to the driving circuit 224. The driving circuit 224 may be configured to drive the power transmission element 214 based on an input voltage signal (VD) 225 at, for example, a resonance frequency of the power transmission element 214. The driving circuit 224 may be a switching amplifier configured to receive a square wave from the oscillator 222 and output a sine wave. The front-end circuit 226 may include a filter circuit configured to filter out harmonics or other undesirable frequencies. The front-end circuit 226 may include a matching circuit configured to match the impedance of the transmitter 204 to the impedance of the power transmission element 214. As will be explained in more detail below, the front-end circuit 226 may include a tuning circuit to create a resonant circuit with a power transmission element 214. As the power transmission element 214 is driven, the power transmission element 214 may generate the wireless field 205 to output power wirelessly at a level sufficient to charge the battery 236 or otherwise power the load. The transmitter 204 may further include a controller 240 operatively coupled to the transmission circuit 206 and configured to control one or more aspects of the transmission circuit 206, or to implement other operations related to managing transmission of power. The controller 240 may be a microcontroller or a processor. The controller 240 may be implemented as an application specific integrated circuit (ASIC). The controller 240 may be operatively connected directly or indirectly to each component of the transmission circuit 206. The controller 240 may be further configured to receive information from each of the components of the transmission circuit 206 and perform calculations based on the received information. The controller 240 may be configured to generate control signals (eg, signals 223) for each of the components, which control signals may adjust the operation of the components. Thus, the controller 240 may be configured to adjust or manage power transmission based on the results of operations performed by the controller. The transmitter 204 may further include a memory (not shown) configured to store data, such as instructions for causing the controller 240 to perform certain functions, such as those related to management of wireless power transmission. The receiver 208 (also referred to herein as a power receiving unit, PRU) may include a receiving circuit 210, which may include a front-end circuit 232 and a rectifier circuit 234. The front-end circuit 232 may include a matching circuit configured to match the impedance of the receiving circuit 210 to the impedance of the power receiving element 218. As will be explained below, the front-end circuit 232 may further include a tuning circuit to create a resonant circuit having a power receiving element 218. As shown in FIG. 2, the rectifier circuit 234 may generate a DC power output from an AC power input to charge the battery 236. The receiver 208 and the transmitter 204 may additionally communicate on a separate communication channel 219 (e.g., Bluetooth, Zigbee, Honeycomb, etc.). The receiver 208 and the transmitter 204 may instead use the characteristics of the wireless field 205 to communicate via in-band signaling. The receiver 208 may be configured to determine whether the amount of power transmitted by the transmitter 204 and received by the receiver 208 is suitable for charging the battery 236. In certain embodiments, the transmitter 204 may be configured to generate a predominantly non-radiative field with a direct field coupling coefficient (k) for providing energy transmission. The receiver 208 may be directly coupled to the wireless field 205 and may generate output power for storage or consumption by a battery (or load) 236 coupled to the output or receiving circuit 210. The receiver 208 may further include a controller 250 configured in a similar manner to the transmission controller 240 as described above for managing one or more aspects of the wireless power receiver 208. The receiver 208 may further include a memory (not shown) configured to store data, such as instructions for causing the controller 250 to perform specific functions, such as those related to management of wireless power transmission. As discussed above, the transmitter 204 and the receiver 208 may be separated by a distance and may be configured according to a mutual resonance relationship to minimize transmission loss between the transmitter 204 and the receiver 208. FIG. 3 is a schematic diagram of a portion of the transmission circuit 206 or the reception circuit 210 of FIG. 2 according to an illustrative embodiment. As illustrated in FIG. 3, the transmission or reception circuit 350 may include a power transmission or reception element 352 and a tuning circuit 360. The power transmitting or receiving element 352 may also be referred to or configured as an antenna or "loop" antenna. The term "antenna" generally refers to a component that can wirelessly output or receive energy for coupling to another "antenna". The power transmitting or receiving element 352 may also be referred to herein or configured as a "magnetic" antenna, or part of an induction coil, resonator, or resonator. The power transmitting or receiving element 352 may also be referred to as a type of coil or resonator configured to wirelessly output or receive power. As used herein, the power transmitting or receiving element 352 is an example of a "power transmission component" of the type configured to wirelessly output and / or receive power. The power transmitting or receiving element 352 may include an air core or a solid core such as an iron core (not shown in this figure). When the power transmitting or receiving element 352 is configured as a resonant circuit or resonator having a tuning circuit 360, the resonance frequency of the power transmitting or receiving element 352 may be based on inductance and capacitance. The inductance may be only the inductance created by the coils and / or other inductors forming the power transmitting or receiving element 352. Capacitance (eg, a capacitor) may be provided by the tuning circuit 360 to create a resonant structure at a desired resonant frequency. As a non-limiting example, the tuning circuit 360 may include a capacitor 354 and a capacitor 356 that may be added to the transmitting and / or receiving circuit 350 to create a resonant circuit. The tuning circuit 360 may include other components to form a resonant circuit having a power transmitting or receiving element 352. As another non-limiting example, the tuning circuit 360 may include a capacitor (not shown) placed in parallel between two terminals of the circuit 350. Other designs are still possible. In some embodiments, the tuning circuit in the front-end circuit 226 may have the same design as the tuning circuit in the front-end circuit 232 (eg, 360). In other embodiments, the front-end circuit 226 may use a different tuning circuit design than the front-end circuit 232. For the power transmitting element, a signal 358 having a frequency substantially corresponding to the resonance frequency of the power transmitting or receiving element 352 may be an input to the power transmitting or receiving element 352. For the power receiving element, a signal 358 having a frequency substantially corresponding to the resonance frequency of the power transmitting or receiving element 352 may be an output from the power transmitting or receiving element 352. Although the aspects disclosed herein may be generally directed to resonant wireless power transmission, the aspects disclosed herein may be used in non-resonant implementations of wireless power transmission. 4A and 4B illustrate examples of an electronic device 40 (for example, a smart phone, a tablet computer, a laptop computer, etc.) according to the present invention. The electronic device 40 may include a rear case (housing) 400 that houses electronic devices (not shown) including the electronic device 40. In some embodiments, the back case 400 may be metal (metal back cover). In some embodiments, the back shell 400 may be divided into several metal portions 402a, 402, 402b. Portions 402a and 402 may be separated to define a space or gap 404. A communication antenna (not shown) may be aligned with respect to the gap 404 to enable transmission and reception of communication signals. Similarly, portions 402 and 402b may be separated to define a space or gap 406 for additional communication antennas (not shown). The metal portion 402 may include a conductor (structure) formed to define a portion of the back case 400. According to the present invention, the metal portion 402 may have the shape of an open loop 412 to define a power receiving element. FIG. 4B shows, for example, that the metal portion 402 may define an opening 408 formed via the metal portion 402. The opening 408 may be used, for example, to hold a lens of a camera (not shown). The groove 410 is defined by and formed via the metal portion 402 and extends between the openings 408, and an edge at the periphery of the metal portion 402 may define an open loop 412. The current 422 represents an eddy current, which is explained below. FIG. 5 is a schematic representation showing additional details of the metal portion 402 according to an aspect of the present invention. In some embodiments, for example, the metal portion 402 may be electrically connected to the capacitor C ₁ , thereby creating a circuit 512. As depicted in FIG. 5, (e.g.) the metal portion 402 is formed with an open loop 412 (FIG. 4B) of the shape of the metallic part 402 may be modeled as a resistor R _model L _model with the inductor connected in series. The capacitor C ₁ turns on the circuit 512. In some embodiments, the power receiving element 502 may be defined by a multi-turn coil of conductive material wound around the opening 408. The power receiving element 502 may be attached to the inner surface of the metal portion 402 or otherwise placed close to the inner surface of the metal portion 402. In some embodiments, the power receiving element 502 may be connected to a capacitor C ₂ . It should be understood that in various embodiments, other circuits or circuit elements may replace the capacitor C ₂ . In some embodiments (not shown), capacitor C ₂ may be omitted. In some embodiments, a means for rectifying may be connected to the power receiving element 502. For example, the rectifier 504 may be connected to a combination of the power receiving element 502 and the capacitor C ₂ to define a circuit that is electrically isolated from the circuit 512. Rectifier 504 may be used in rectifying the power receiving device 502 of current (AC) signal to produce direct current (DC) of any suitable design output voltage V _out (DC power). The output voltage V _out can be provided to a load 506 in the electronic device (40, FIG. 4A). In some embodiments, a coil of conductive material containing the power receiving element 502 may be wound around the opening 408 adjacent to the opening 408. In other embodiments, the power receiving element 502 may be wound around a larger perimeter to include a larger area than the opening 408. FIG. 5A shows, for example, that the power receiving element 502 can be wound around the periphery of the metal portion 402. It should be understood that in other embodiments, the periphery of the power receiving element 502 may be anywhere between the opening 408 and the periphery of the metal portion 402. Referring to FIG. 6, in operation, when the metal portion 402 is exposed to an externally generated magnetic field (for example, the wireless field 105 of the wireless power transmission system 100 shown in FIG. 1), the metal portion 402 may be coupled to the externally generated magnetic field and In response to the coupling, a current (eg, eddy current) may be induced in the metal portion 402. This current is schematically represented as a current 602 in the circuit 512 in the figure. For comparison purposes, FIG. 4B shows how the induced current 422 can flow in the metal portion 402 when the capacitor C ₁ is omitted. By reviewing the metal part 402, it can be modeled as a series connection of a resistor R _model and an inductor L _model . The capacitor C ₁ connected in series with the inductor L _model can cancel or at least significantly reduce the reactance presented by the inductor L _model . In principle, if the capacitance of capacitor C _{1 is} appropriately selected, the reactance components of L _model and C ₁ (respectively j wL _model and 1 / j wC ₁ ) will cancel each other, leaving a pure resistance component (ie, R _model ). Cancelling or at least significantly reducing the reactance component in the circuit 512 may increase the current 602 induced in the metal portion 402 and thereby enhance wireless power transmission. The current 602 induced in the metal portion 402 may then create a magnetic field (induced magnetic field) diverging from the metal portion 402, which is represented schematically by the shaded area 604 in FIG. Therefore, the metal portion 402 may serve as a member for generating a magnetic field (ie, an induced magnetic field 604). The power receiving element 502 may then be coupled to the induced magnetic field 604 to form a current 606 in the power receiving element 502. Therefore, the power receiving element 502 may serve as a means for generating the current 606. A suitable rectifier (eg, rectifier 504) can be used to rectify the current 606 induced in the power receiving element 502 to generate a DC voltage V _out that can be used to power a load 506 (eg, device electronics, batteries, etc.). Therefore, a properly selected capacitor C ₁ can maximize the current 602 induced in the metal portion 402 and then maximize the induced magnetic field 604 that can be coupled by the power receiving element 502. According to the present invention, the metal portion 402 of the resonance frequency can be appropriately selected by the capacitance of _a capacitor C to tune ( "tuning" the metal portion 402) to set the resonant frequency of the circuit 512. At resonance, the reactance components L _model and C ₁ substantially cancel at a specific frequency. Similarly, the resonance frequency of the power receiving element 502 can be tuned by a suitable selection for the capacitance of the capacitor C ₂ to set the resonance frequency of a circuit including the power receiving element 502. Referring to FIG. 6A, according to the present invention, the self-transmission coil can be controlled by changing the mutual inductance M1 (and the resulting coupling) between the transmission coil and the metal portion 402 and / or the mutual inductance M2 between the metal portion 402 and the power receiving element 502. (For example, in the power transmission element 114, FIG. 1) the power transmission to the power receiving element 502 (for example, the amount of power transferred and the efficiency of the transfer). For example, the coupling between the transmission coil and the power receiving element 502 can be maximized by maximizing both the mutual inductance M1 between the transmission coil and the metal portion 402 and the mutual inductance M2 between the metal portion 402 and the power receiving element 502. For power transmission. The maximum mutual inductance can be achieved by setting the resonance frequency of both the metal portion 402 and the power receiving element 502 to be substantially equal to the frequency of an externally generated magnetic field generated by the transmission coil. In some cases, less than the maximum power transmission may be desirable. The degree of power transmission can be controlled by reducing mutual inductance. For example, the resonance frequency of the metal portion 402 can be set to a frequency different from the frequency of a magnetic field (called "resonance resonance") generated externally to reduce the mutual inductance M1 between the transmission coil and the metal portion 402, and at the same time, The resonance frequency of the power receiving element 502 is substantially equal to the frequency of a magnetic field generated from the outside. Reducing the mutual inductance M1 between the transmission coil and the metal portion 402 may have the overall effect of reducing the power transmission from the transmission coil to the power receiving element 502. On the contrary, the resonance frequency of the metal portion 402 can be kept substantially equal to the frequency of the externally generated magnetic field, and the resonance frequency of the power receiving element 502 can be set to a frequency different from the frequency of the externally generated magnetic field to reduce the metal portion 402 and The mutual inductance M2 between the power receiving elements 502. In some embodiments, the mutual inductances M2 and M2 between the transmission coil and the metal portion 402 can be reduced, for example, by tuning both the metal portion 402 and the power receiving element 502 to a frequency partial resonance with respect to a magnetic field generated externally. Both the mutual inductance between the metal portion 402 and the power receiving element 502. Referring back to FIGS. 5, 5A and 6, showing schematically depicts a metal portion 402 is electrically connected to the capacitor C _1. In some embodiments, the capacitor C ₁ may be directly connected (eg, soldered) to the metal portion 402. In other embodiments, attaching the capacitor C ₁ directly to the metal portion 402 may not be practical. Thus, Example 7 illustrates capacitors C ₁ a specific embodiment of the metal tuning portion 402 according to other embodiments of the present invention. The tuning element 712 may be disposed on a printed circuit board (PCB) 702 containing device electronics of an electronic device (eg, 40, FIG. 4A). A connector 714 (eg, a spring-loaded thimble) attached to the PCB 702 and connected to the tuning element 712 may extend from the tuning element 712 to make electrical contact with a contact 716 formed on the metal portion 402, thereby electrically tuning the tuning element 712 Connected to the metal portion 402. In various embodiments, the tuning element 712 may be any suitable circuit or circuit element. In some embodiments, for example, the tuning element 712 may be a capacitor such as capacitor C ₁ (FIG. 5). In other embodiments, the tuning element 712 may include a variable capacitor, a capacitor network (including capacitors connected in series, capacitors connected in parallel), and the like. As mentioned above, the metal portion 402 has an inductance L _model (FIG. 5) associated with the metal portion by the shape of the metal portion's loop 412 (FIG. 4B). In some embodiments, the inductance of the metal portion 402 may be changed. Therefore, in some embodiments, the tuning element 712 may include one or more inductive elements to increase or decrease the total inductance presented by the metal portion 402 and the tuning element 712. According to the present invention, the roles of the metal portion 402 and the power receiving element 502 can be reversed. Referring to FIG. 8, for example, in some embodiments, the metal portion 402 may function as a power receiving element 802. A rectifier 814 may be connected to the metal portion 402 to define a circuit 812. In some embodiments, a tuning capacitor C ₁ (or other tuning circuit) may be added to the circuit 812, for example, to tune the resonant frequency of the circuit 812. The means for generating a magnetic field may include a coil 804 of conductive material wound around the opening 408. Capacitor C ₂ may be connected to coil 804 to tune the resonant frequency of the circuit defined by coil 804 and capacitor C ₂ . As described above, the self-transmission coil can be controlled by controlling the mutual inductance between the transmission coil and the power receiving element 802 and / or the mutual inductance between the power receiving element 802 and the coil 804 (e.g., the power transmission element 114, FIG. 1) Power transmission to the power receiving element 802. For example, the power receiving element 802 may be tuned (for example, by tuning C ₁ ) to a resonance or off-resonance with respect to a frequency of an external magnetic field generated by the transmission coil to change the transmission coil and power receiving element 802. Mutual inductance. Similarly, the coil 804 may be tuned (eg, by tuning C ₂ ) to a resonance or off-resonance with respect to the frequency of the external magnetic field to modify the mutual inductance between the power receiving element 802 and the coil 804. Referring to Figure 8A, in other embodiments, the coil 804 may be omitted, leaving only includes a power receiving element 802 (implemented using a metal portion 402), a capacitor C ₁ and the resonant circuit 812 of the rectifier 814. 9 and FIG. 9A, an embodiment according to the present invention may include a wearable electronic device. For example, in some embodiments, the wearable electronic device 90 may include a device body 92 connected to the fastener 94. The wearable electronic device 90 may be a smart watch, a health monitoring device, or the like. The device body 92 may include a metal portion 902. The metal portion 902 may have an open loop shape defining a central opening 908 and a groove 910 connecting the opening 908 and the periphery of the metal portion 902. Capacitor C ₁ may be connected to metal portion 902 to define a circuit tuned by capacitor C ₁ . The device body 92 may include a power receiving element (eg, a coil) 912 wound around the opening 908. The power receiving element 912 may be connected to the capacitor C ₂ (for example, to tune the power receiving element 912), and connected to the rectifier 904 to generate current using the current induced in the power receiving element 912 when the power receiving element 912 is exposed to an externally generated magnetic field. DC voltage V _out . In some embodiments, the metal portion 902 can serve as a housing to house a device electronics (not shown) containing the wearable electronic device 90. Referring to FIG. 9A, in other embodiments, the wearable electronic device 91 may include a device body 93. The device body may include a non-metallic housing 96 for receiving the metal portion 902 and the power receiving element 912. As described above, the self-transmission coil can be controlled by controlling the mutual inductance between the transmission coil and the power receiving element 912 and / or the mutual inductance between the power receiving element 912 and the metal portion 902 (for example, the power transmission element 114, FIG. 1 ) Power transmission to the power receiving element 912. For example, the power receiving element 912 may be tuned (for example, by tuning C ₂ ) to a resonance or off-resonance with respect to the frequency of an external magnetic field generated by the transmission coil to change the transmission coil and power receiving element 912. Mutual inductance. Similarly, the metal portion 902 may be tuned (eg, by tuning C ₁ ) to a resonance or off-resonance with respect to the frequency of the external magnetic field to modify the mutual inductance between the power receiving element 912 and the metal portion 902. 10, an embodiment according to the present invention may include a portable computer; for example, a laptop computer, a tablet computer, and the like. For example, in some embodiments, the portable computer 10 may include a front case 1002 and a back case 1008 for receiving the display 1004 and device electronics (eg, circuits, batteries, etc.) 1006, and a wireless power receiver 1010. The rear case 1008 may be a non-metal material so as not to interfere with the wireless power receiving function. Details of the wireless power receiver 1010 according to the present invention will now be described. 11A and 11B are schematic representations showing details of a wireless power receiver 1010 according to an embodiment of the present invention. The wireless power receiver 1010 may include a metal portion 1102 having a shape of an open loop defining an opening 1108 and a slot 1110 extending between the opening 1108 and a periphery of the metal portion 1102. A power receiving element (eg, a coil) 1112 may be wound around the opening 1108. The rectifier 1104 may be connected to the power receiving element 1112 to generate a DC voltage V _out from a current, and the current may be generated in the power receiving element 1112 in response to an externally generated magnetic field. The ferrite layer 1122 may be disposed between the power receiving element 1112 and the device electronics 1006 so as to prevent the magnetic field that can be generated by the power receiver 1010 from coupling the device electronics 1006. The ferrite layer 1122 is omitted in FIG. 11B to explain the details of the metal portion 1102 more clearly. The capacitor C ₁ may be used to tune the metal portion 1102 to resonate with or not to a magnetic field generated externally, so as to modify the mutual inductance between the metal portion 1102 and the transmission coil. Likewise, the capacitor C ₂ can be used to tune the power receiving member 1112 with or without a magnetic field generated by the external resonator, 1112 to change the mutual inductance between the power receiving portion 1102 and the metal member. According to an embodiment of the present invention, the power receiver 1010 may have an area smaller than that of the portable computer 10 shown in FIG. 10. In some embodiments, the area of the power receiver 1010 may be less than 50% of the area of the portable computer 10. Due to the amplification effect of the tuned metal portion 1102, the coil 1112 can be more strongly coupled to an externally generated magnetic field, and thus realizes power transmission than a wireless power transmission system that does not use an amplification element such as the tuned metal portion 1112. Greater power transmission. Therefore, the power receiver 1010 may be smaller and still achieve a similar power transmission equivalent to a larger wireless power transmission system. The above description illustrates various embodiments of the invention, along with examples of how specific embodiments may be implemented. The above examples should not be considered as the only embodiments, and the above examples are presented to illustrate the flexibility and advantages of specific embodiments that are limited by the scope of the accompanying patent application. Based on the above disclosure and the scope of the accompanying patent application, other configurations, embodiments, implementations, and equivalents can be used without departing from the scope of the invention defined by the scope of the patent application.

10‧‧‧Portable Computer
40‧‧‧electronic device
90‧‧‧ Wearable electronic device
91‧‧‧ Wearable electronic device
92‧‧‧device body
93‧‧‧device body
94‧‧‧Fastener
96‧‧‧ Non-metallic housing
100‧‧‧Wireless Power Transmission System
102‧‧‧input power
104‧‧‧Transmitter
105‧‧‧Wireless Field
108‧‧‧ Receiver
110‧‧‧Output power
112‧‧‧distance
114‧‧‧Power Transmission Element
118‧‧‧Power receiving element
200‧‧‧Wireless Power Transmission System
204‧‧‧Transmitter
205‧‧‧Wireless Field
206‧‧‧Transmission circuit
208‧‧‧Receiver
210‧‧‧Receiving circuit
214‧‧‧Power Transmission Element
218‧‧‧Power receiving element
219‧‧‧Single communication channel
222‧‧‧Oscillator
223‧‧‧Frequency control signal
224‧‧‧Drive circuit
225‧‧‧Input voltage signal
226‧‧‧Front end circuit
232‧‧‧Front end circuit
234‧‧‧Rectifier circuit
236‧‧‧ Battery
240‧‧‧ Controller
250‧‧‧ Controller
350‧‧‧Transmit and / or Receive Circuit
352‧‧‧Power transmission or receiving element
254‧‧‧Capacitor
356‧‧‧Capacitor
358‧‧‧Signal
360‧‧‧ Tuning Circuit
400‧‧‧back case
402‧‧‧metal parts
402a‧‧‧metal parts
402b‧‧‧metal parts
404‧‧‧Space / Gap
406‧‧‧Space / Gap
408‧‧‧ opening
410‧‧‧slot
412‧‧‧ open loop
422‧‧‧Current
502‧‧‧Power receiving element
504‧‧‧ Rectifier
506‧‧‧Load
512‧‧‧circuit
602‧‧‧ current
604‧‧‧Shadow area / Induced magnetic field
606‧‧‧current
702‧‧‧printed circuit board
712‧‧‧ Tuning Element
714‧‧‧connector
716‧‧‧Contact
802‧‧‧ Power receiving element
812‧‧‧circuit
814‧‧‧ Rectifier
902‧‧‧metal parts
904‧‧‧ Rectifier
908‧‧‧ opening
910‧‧‧slot
912‧‧‧Power receiving element
1002‧‧‧Front shell
1004‧‧‧Display
1006‧‧‧device electronics
1008‧‧‧Back case
1010‧‧‧Wireless Power Receiver
1102‧‧‧Metal Parts
1104‧‧‧ Rectifier
1108‧‧‧ opening
1110‧‧‧slot
1112‧‧‧ Power receiving element / coil / tuned metal part
1122‧‧‧ferrite layer
C ₁ ‧‧‧Capacitor
C ₂ ‧‧‧Capacitor
L _model ‧‧‧Inductance
M1‧‧‧ Mutual inductance between transmission coil and metal part
M2‧‧‧ Mutual inductance between metal part and power receiving element
R _model resistance
V _out ‧‧‧DC output voltage

Regarding the drawings discussed below and in detail, it should be emphasized that the details shown represent examples for the purpose of illustrative discussion and are presented to provide a description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show implementation details beyond the basic understanding of the present invention. In conjunction with the drawings, the following discussion will make apparent to those skilled in the art how embodiments may be practiced in accordance with the present invention. Similar or identical reference numbers may be used to identify similar or identical elements that are otherwise referred to in various drawings or support the description. In the accompanying drawings: FIG. 1 is a functional block diagram of a wireless power transmission system according to an illustrative embodiment. FIG. 2 is a functional block diagram of a wireless power transmission system according to an illustrative embodiment. 3 is a schematic diagram of a portion of the transmission circuit or the reception circuit of FIG. 2 including a power transmission or reception element according to an illustrative embodiment. 4A and 4B show a rear case according to the present invention. 5 and 5A illustrate details of an embodiment according to the present invention. FIG. 6 illustrates eddy currents in an embodiment according to the present invention. FIG. 6A illustrates the configuration shown in FIG. 6 as a three-coil coupling configuration. FIG. 7 shows a specific implementation according to an embodiment of the invention. 8 and 8A illustrate an alternative embodiment according to the present invention. 9 and 9A illustrate details of a wearable embodiment according to the present invention. FIG. 10 illustrates details of an embodiment of a portable computer according to the present invention. 11A and 11B show details of an embodiment according to the present invention.

402‧‧‧metal parts

408‧‧‧ opening

502‧‧‧Power receiving element

504‧‧‧ Rectifier

506‧‧‧Load

512‧‧‧circuit

C ₁ ‧‧‧Capacitor

C ₂ ‧‧‧Capacitor

L _model ‧‧‧Inductance

R _model ‧‧‧ resistance

V _out ‧‧‧DC output voltage

Claims (30)

An electronic device for wireless power transmission, the device comprising: a conductor configured to be magnetically coupled to a first magnetic field; a first tuning element electrically connected to the conductor; and a conductive coil, It is wound around an opening defined by the electrical conductor, and the conductive coil is configured to be magnetically coupled to a second magnetic field. The device of claim 1, further comprising a second tuning element electrically connected to the conductive coil. The device of claim 2, wherein each of the first tuning element and the second tuning element includes one or more capacitors. The device of claim 3, wherein either or both of the first tuning element and the second tuning element include one or more inductors. The device of claim 1, wherein the first magnetic field is an externally generated magnetic field generated by a wireless power transmitter and the conductor is configured to generate the second magnetic field in response to the externally generated magnetic field coupled to the externally generated magnetic field. The device of claim 5, further comprising a rectifier connected to the conductive coil, the rectifier configured to rectify a current induced in the conductive coil to provide power to an electronic device including the device. The device of claim 1, wherein the second magnetic field is an externally generated magnetic field and the conductive coil is configured to generate the first magnetic field in response to being coupled to the externally generated magnetic field, the device further comprising a connection to the conductive A rectifier configured to rectify the current induced in the electrical conductor to provide power to an electronic device containing the device. The device of claim 1, further comprising: a printed circuit board on which the first tuning element is placed; and a connector that electrically connects the first tuning element to the conductor. The device of claim 1, further comprising a printed circuit board, the conductive coil being disposed between the conductor and the printed circuit board. The device of claim 9, further comprising a ferrite material disposed between the conductive coil and the printed circuit board. The device of claim 1, wherein the first tuning element and the electrical conductor constitute a circuit having a resonant frequency defined by the first tuning element. The device of claim 11, further comprising a second tuning element, the second tuning element being electrically connected to the conductive coil to define a circuit having a circuit substantially equal to the first tuning element and the conductive body. A resonant frequency of the resonant frequency of the circuit. The device of claim 11, further comprising a second tuning element electrically connected to the conductive coil to define a circuit having a circuit different from the circuit including the first tuning element and the conductor A resonance frequency of the resonance frequency. The device of claim 1, further comprising a metal casing configured to receive the electronic device, the metal casing containing the electrical conductor. The device of claim 1, further comprising a non-metallic shell configured to contain electronic devices containing the device, and the conductor and the conductive coil are housed within the shell. The device of claim 1, wherein the device is a wearable electronic device. A method for transmitting wireless power to an electronic device, the method comprising: magnetically coupling to an externally generated magnetic field via a conductive structure including a housing for the electronic device to generate a magnetic field emitted from the conductive structure; An inductive magnetic field; magnetically coupled to the inductive magnetic field via a power receiving element to sense a current in the power receiving element, the power receiving element being electrically isolated from the conductive structure; and generated from the current induced in the power receiving element electric power. The method of claim 17, wherein a resonance frequency of a circuit including the conductive structure is substantially equal to a frequency of the externally generated magnetic field. The method of claim 17, wherein a resonance frequency of a circuit including the power receiving element is substantially equal to a frequency of the externally generated magnetic field. The method of claim 17, wherein magnetically coupling to the externally generated magnetic field via the conductive structure comprises inducing a current in a first circuit including one of the conductive structures electrically connected to a first tuning element, wherein the power receiving element Magnetically coupling to the inductive magnetic field includes inducing a current in a second circuit including one of the power receiving elements electrically connected to a second tuning element. The method of claim 20, wherein a resonance frequency of either or both of the first circuit and the second circuit is substantially equal to a frequency of the externally generated magnetic field. The method of claim 17, wherein generating power includes rectifying the current induced in the power receiving element. A device for wirelessly receiving power, the device comprising: a housing configured to enclose an electronic component containing the device, the housing including a metal portion; a first tuning element connected to the housing The metal part of the body, the metal part of the casing has a shape in response to a magnetic field coupled to an externally generated magnetic field so that an electric current is induced in the casing, and an induced magnetic field responds to the current The metal portion diverges; a conductive coil, in response to being magnetically coupled to the inductive magnetic field, a current is induced in the conductive coil; and a rectifier configured to rectify the current induced in the conductive coil to convert power Provided to a load. The device of claim 23, wherein the metal portion of the housing defines an opening therethrough and a slot from the opening to a periphery of the metal portion. The device of claim 23, wherein the rectifier is electrically connected to the conductive coil. The device of claim 23, wherein the first tuning element and the metal portion of the housing define a resonance frequency substantially equal to a resonance frequency defined by a second tuning element and the conductive coil. The device of claim 23, wherein the first tuning element and the metal portion of the housing define a resonance frequency different from a resonance frequency defined by a second tuning element and the conductive coil. A device for wirelessly receiving power in an electronic device, the device comprising: a component for accommodating an electronic device of the electronic device, the components for accommodating have a metal part, the metal part includes a magnetic part for magnetic coupling A component to an externally generated magnetic field to generate an induced magnetic field, the induced magnetic field diverging from the component for magnetic coupling to the externally generated magnetic field, wherein the component for magnetic coupling to the externally generated magnetic field is electrically connected to the component; A component for tuning the component magnetically coupled to the externally generated magnetic field to resonate at a resonant frequency; a component for magnetic coupling to the induced magnetic field to induce a current, for magnetically coupling to the induced magnetic field The component is electrically isolated from the component for magnetic coupling to the externally generated magnetic field; and a component for generating electricity from the current induced in the component for magnetic coupling to the induced magnetic field. The device of claim 28, wherein either or both of the member for magnetic coupling to the externally generated magnetic field and the member for magnetic coupling to the induced magnetic field have a magnetic field substantially equal to the externally generated magnetic field A resonant frequency at one frequency. The apparatus of claim 28, wherein the member for magnetically coupling to the induced magnetic field includes a conductive coil.